%aplanar(+Xs, -Ys)
aplanar([], []).
aplanar([X|XS], YS) :- is_list(X), aplanar(X, XAplanada), aplanar(XS, ZS), append(XAplanada, ZS, YS).
aplanar([X|XS], YS) :- not(is_list(X)), aplanar(XS, ZS), append([X], ZS, YS).
